High-pressure pump

ABSTRACT

In a high-pressure pump, a relief valve main body has a rod shape. A relief valve seat portion is integrated with an end of a relief valve main body so as to be capable of contacting a relief valve seat. The relief valve main body is inserted into a guide hole portion of a support portion. The guide hole portion slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve main body in the axial direction. A fuel guide portion is provided at an end portion of the relief valve main body facing the pressurizing chamber and can guide a flow of the fuel in a direction radially outward of the relief valve main body on the way from the pressurizing chamber toward the valve seat portion.

CROSS REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of International ApplicationNo. PCT/JP2016/002290 filed on May 10, 2016, which designated the U.S.and claims priority to Japanese Patent Application No. 2015-117497 filedon Jun. 10, 2015, the entire contents of each of which are herebyincorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a high-pressure pump that pressurizesand discharges a fuel.

BACKGROUND ART

Up to now, a high-pressure pump has been known, in which a dischargevalve and a relief valve are integrated with each other in a dischargepassage through which a fuel pressurized in a pressurizing chamberflows. For example, in a high-pressure pump disclosed in PatentLiterature 1, a spherical valve body is used as a valve body of therelief valve.

The high-pressure pump of Patent Literature 1 includes a holder thatholds the valve body of the relief valve and an urging member that urgesthe valve body toward a valve seat through the holder. In this case, themovement of the valve body and the holder is not guided by anothermember, and can move relatively freely in a space between thepressurizing chamber and the valve seat. The fuel discharged from thepressurizing chamber of the high-pressure pump flows around the valvebody and the holder to be discharged to the outside of the high-pressurepump. For that reason, the valve body and the holder may move or vibratedue to a flow of the fuel. If the valve body moves or vibrates in astate where the valve body is in contact with the valve seat, the valveseat or the valve body may be worn. If the valve seat or the valve bodywears, a valve opening pressure of the relief valve may change overtime.

PRIOR ART LITERATURE Patent Literature

Patent Literature 1: JP 5501272 B

SUMMARY

In the high-pressure pump of Patent Literature 1, for example, if thevalve body is formed in a rod shape and an outer wall of the valve bodyis slidably supported on an inner wall of a hole portion so as to guidea reciprocating movement of the valve body in an axial direction, it isconceivable that wear of the valve seat or the valve body describedabove can be reduced. However, in such a configuration, the fueldischarged from the pressurizing chamber and flowing through thedischarge passage from the pressurizing chamber toward the outside ofthe high-pressure pump may enter a space between the inner wall of thehole portion and the outer wall of the valve body. When the fuel entersthe space between the hole portion and the valve body, air bubbles aregenerated between the hole portion and the valve body duringreciprocating movement of the valve body, the air bubbles collapse,cavitation erosion may occur in the inner wall of the hole portion orthe outer wall of the valve body, and the hole portion or the valve bodymay be eroded. As a result, backlash between the hole portion and thevalve body increases, and the valve body moves or vibrates in a statewhere the valve body contacts the valve seat, so that the valve seat orthe valve body may be worn. As described above, even with theconfiguration considered as a countermeasure against the problem ofPatent Literature 1, the same problem as that of Patent Literature 1 mayarise after a long period of time.

The present disclosure has been made in view of the above-describedpoints, and an object of the present disclosure is to provide ahigh-pressure pump capable of reducing a change over time in valveopening pressure of a relief valve member over a long period of time.

According to an aspect of the present disclosure, a high-pressure pumpincludes a pump body, a valve seat portion, a discharge valve member, adischarge valve urging member, a relief valve member, a relief valveurging member and a support portion. The pump body includes apressurizing chamber that pressurizes a fuel, and a discharge passagethrough which the fuel pressurized and discharged by the pressurizingchamber flows. The valve seat portion includes a valve seat main body, adischarge valve passage, a relief valve passage, a discharge valve seatand a relief valve seat.

The valve seat main body is provided in the discharge passage topartition the discharge passage into a first space positioned betweenthe valve seat main body and the pressurizing chamber and a second spacepositioned on an opposite side of the valve seat main body from thepressurizing chamber. The discharge valve passage is provided in thevalve seat main body and connects the first space and the second space.The relief valve passage which is provided in the valve seat main bodyand connects the second space and the first space without communicatingwith the discharge valve passage. The discharge valve seat has anannular shape and surrounds an opening of the discharge valve passage ofthe valve seat main body in the second space. The relief valve seat hasan annular shape and surrounds an opening of the relieve valve passageof the valve seat main body in the first space. The discharge valvemember is provided in the second space to be capable of contacting thedischarge valve seat, and the discharge valve member opens or closes thedischarge valve passage when separating from the discharge valve seat orcontacting the discharge valve seat. The discharge valve urging memberurges the discharge valve member toward the discharge valve seat. Therelief valve member includes a relief valve main body and a relief valveseat portion.

The relief valve main body has a rod shape. The relief valve seatportion is integrated with a first end of the relief valve main body inthe axial direction and is capable of contacting the relief valve seat.The relief valve member is provided in the first space to bereciprocable in an axial direction. The relief valve urging member urgesthe relief valve member toward the relief valve seat. The supportportion includes a support main body and a guide hole portion.

The support main body is provided in the first space. The guide holeportion connects a surface of the support main body facing thepressurizing chamber and a surface of the support main body facing thevalve seat portion. The relief valve main body is inserted into theguide hole portion. The support portion slidably supporting an outerwall of the relief valve main body by the guide hole portion to guidereciprocating movement of the relief valve member in the axialdirection. The fuel guide portion is provided on an end portion of therelief valve main body facing the pressurizing chamber and is capable ofguiding a flow of the fuel in a direction radially outward of the reliefvalve main body on the way from the pressurizing chamber to the valveseat portion.

In the above aspect of the present disclosure, the guide hole portion ofthe support portion slidably supports the outer wall of the relief valvemain body so as to guide the reciprocating movement of the relief valvemember in the axial direction. For that reason, even if the fueldischarged from the pressurizing chamber in the high-pressure pump flowsaround the relief valve member, the relief valve seat portion of therelief valve member is prevented from relatively moving or oscillatingin the radial direction with respect to the relief valve seat. As aresult, wear of the relief valve seat or the relief valve seat portioncan be reduced. Therefore, a change over time in the valve openingpressure of the relief valve member can be reduced.

In the above aspect of the present disclosure, for example, when thefuel is discharged from the pressurizing chamber, the fuel passing bythe fuel guide portion from the pressurizing chamber toward the valveseat portion flows in the direction radially outward of the relief valvemain body. For that reason, the fuel can be prevented from entering aspace between the inner wall of the guide hole portion and the outerwall of the relief valve main body. As a result, cavitation erosionbetween the guide hole portion and the relief valve main body can bereduced, and the guide hole portion or the relief valve main body can beprevented from being eroded. As a result, the backlash between the guidehole portion and the relief valve main body can be prevented fromincreasing even after a long period of time, and the relief valve seator the relief valve seat portion can be prevented from being worn. As aresult, according to the present disclosure, a change over time in thevalve opening pressure of the relief valve member can be reduced for along period of time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a high-pressure pump according toa first embodiment of the present disclosure.

FIG. 2 is a cross-sectional view showing a high-pressure pump accordingto the first embodiment.

FIG. 3 is a diagram showing a portion III of FIG. 2.

FIG. 4 is a cross-sectional view showing a vicinity of a relief valveseat in the high-pressure pump according to the first embodiment.

FIG. 5 is a cross-sectional view showing a vicinity of a fuel guideportion of the high-pressure pump according to the first embodiment.

FIG. 6 is a cross-sectional view showing a discharge valve device of thehigh-pressure pump according to the first embodiment, showing a state inwhich a fuel flows toward a fuel rail through a discharge valve seat.

FIG. 7 is a cross-sectional view showing the discharge valve device ofthe high-pressure pump according to the first embodiment, showing astate in which the fuel flows toward the pressurizing chamber throughthe relief valve seat.

FIG. 8 is a cross-sectional view showing a vicinity of a fuel guideportion in a high-pressure pump according to a second embodiment of thepresent disclosure.

FIG. 9 is a cross-sectional view showing a vicinity of a fuel guideportion in a high-pressure pump according to a third embodiment of thepresent disclosure.

DESCRIPTION OF EMBODIMENTS

Hereinafter, multiple embodiments for implementing the presentdisclosure will be described referring to drawings. In the respectiveembodiments, a part that corresponds to a matter described in apreceding embodiment may be assigned the same reference numeral, andredundant explanation for the part may be omitted. When only a part of aconfiguration is described in an embodiment, another precedingembodiment may be applied to the other parts of the configuration. Theparts may be combined even if it is not explicitly described that theparts can be combined. The embodiments may be partially combined even ifit is not explicitly described that the embodiments can be combined,provided there is no harm in the combination.

First Embodiment

A high-pressure pump according to a first embodiment of the presentdisclosure is illustrated in FIG. 2.

A high-pressure pump 1 is provided in a vehicle not shown. Thehigh-pressure pump 1 is a pump that supplies a fuel at a high pressureto an engine, for example, as an internal combustion engine. The fuelsupplied to the engine by the high-pressure pump 1 is, for example,gasoline. In other words, a fuel supply target of the high-pressure pump1 is a gasoline engine.

As illustrated in FIG. 1, the fuel stored in the fuel tank 2 is suppliedto the high-pressure pump 1 through a pipe 4 by a fuel pump 3. Thehigh-pressure pump 1 pressurizes the fuel supplied from the fuel pump 3and discharges the pressurized fuel to a fuel rail 7 through a pipe 6.As a result, the fuel in the fuel rail 7 is accumulated and injected andsupplied to the engine from fuel injection valves 8 connected to thefuel rail 7. As illustrated in FIG. 2, the high-pressure pump 1 includesa pump body 10, a cover 15, a pulsation damper 16, a plunger 20, anintake valve device 30, an electromagnetic drive portion 40, a dischargevalve device 50, and the like. The pump body 10 includes an upperhousing 11, a lower housing 12, a cylinder 13, a holder support portion14, a union 51, and the like.

The upper housing 11 is formed in a substantially rectangularparallelepiped block shape and made of a metal such as stainless steel.The upper housing 11 includes an intake hole portion 111, a dischargehole portion 112, a cylinder hole portion 113, a step portion 114, andthe like. The intake hole portion 111 opens at one end of the upperhousing 11 in a longitudinal direction and is formed in a substantiallycylindrical shape so as to extend in the longitudinal direction. As aresult, an intake passage 101 is formed inside the intake hole portion111. The discharge hole portion 112 opens at the other end of the upperhousing 11 in the longitudinal direction and is formed in asubstantially cylindrical shape so as to extend in the longitudinaldirection. As a result, a discharge passage 102 is provided inside thedischarge hole portion 112. In this example, the intake hole portion 111and the discharge hole portion 112 are coaxially provided.

The cylinder hole portion 113 is formed in a substantially cylindricalshape between the intake hole portion 111 and the discharge hole portion112 so as to open at both end portions of the upper housing 11 in alateral direction. In this example, a space inside the cylinder holeportion 113 is connected to the intake passage 101 and the dischargepassage 102. The step portion 114 is provided on an inner wall of theupper housing 11 provided with the discharge hole portion 112. An innerdiameter of a part of the discharge hole portion 112 extending from thestep portion 114 toward the intake hole portion 111 is smaller than aninner diameter of a part of the discharge hole portion 112 extendingfrom the step portion 114 in a direction away from the intake holeportion 111 (refer to FIGS. 2 and 3).

The lower housing 12 is formed in a plate shape and made of a metal suchas stainless steel. The lower housing 12 includes a cylinder holeportion 121. The cylinder hole portion 121 is formed in a substantiallycircular shape so as to penetrate through the lower housing 12 in aplate thickness direction. The lower housing 12 is provided so as to beengaged with the upper housing 11 so that the cylinder hole portion 113and the cylinder hole portion 121 are coaxially provided. In thisexample, the upper housing 11 and the lower housing 12 correspond to a“housing” in the claims.

The cylinder 13 is formed in a bottomed cylindrical shape and made of ametal such as stainless steel. The cylinder 13 has an intake hole 131and a discharge hole 132. The intake hole 131 and the discharge hole 132are provided in the vicinity of a bottom portion of the cylinder portionof the cylinder 13 so as to face each other. In other words, the intakehole 131 and the discharge hole 132 are formed so as to extend in theradial direction of the cylinder 13 so as to sandwich the axis of thecylinder 13 between the intake hole 131 and the discharge hole 132. Thecylinder 13 is inserted through the cylinder hole portion 113 of theupper housing 11 and the cylinder hole portion 121 of the lower housing12 so that the intake hole 131 is connected to the intake passage 101and the discharge hole 132 is connected to the discharge passage 102. Anouter wall of a bottom end portion of the cylinder 13 is fitted to aninner wall forming the cylinder hole portion 113 of the upper housing11.

The holder support portion 14 is formed in a substantially cylindricalshape and made of a metal such as stainless steel. One end of the holdersupport portion 14 is provided to connect to an opposite side of thelower housing 12 from the upper housing 11 so that the holder supportportion 14 is coaxial with the cylinder 13. In the present embodiment,the holder support portion 14 is formed integrally with the lowerhousing 12.

The union 51 is formed in a substantially cylindrical shape and made ofa metal such as stainless steel. The union 51 is provided such that oneend of the union 51 is inserted into the discharge hole portion 112 ofthe upper housing 11. In the present embodiment, the union 51 hasthreads on the outer wall at one end, and the upper housing 11 has screwgrooves on the inner wall of the discharge hole portion 112. The union51 is fixed to the upper housing 11 by being screwed into the dischargehole portion 112. The union 51 forms the discharge passage 102 therein.Further, the union 51 has a step portion 52. The step portion 52 isformed on an inner wall of the union 51. An inner diameter of a part ofthe union 51 extending from the step portion 52 toward the step portion114 is larger than an inner diameter of another part of the union 51extending from the step portion 52 in a direction away from the stepportion 114 (refer to FIGS. 2 and 3). The other end of the union 51,that is, an end portion of the union 51 opposite from the upper housing11 is connected to an end of the pipe 6 opposite from the fuel rail 7.

The cover 15 is formed in a bottomed cylindrical shape, that is, a cupshape, and made of a metal such as stainless steel. The cover 15accommodates the upper housing 11 therein, and an end portion of thecover 15 on its opening side is connected to an outer edge portion ofthe lower housing 12. The cover 15 and the lower housing 12 areconnected to each other by welding over the entire circumference. As aresult, the cover 15 and the lower housing 12 are liquid-tightly kept. Afuel gallery 100 is formed between the inside of the cover 15 and thelower housing 12. The cover 15 is provided with an inlet portion notshown. A pipe 4 connected to the fuel pump 3 is connected to the inletportion. As a result, the fuel in the fuel tank 2 flows into the insideof the cover 15, that is, into the fuel gallery 100 through the inletportion.

The cover 15 has a first hole 151 and a second hole 152. The first hole151 and the second hole 152 are each formed so as to connect the innerwall and the outer wall of the cover 15. The first hole 151 and thesecond hole 152 are formed at positions corresponding to the intake holeportion 111 and the discharge hole portion 112 of the upper housing 11,respectively. In this example, the union 51 is provided so as to beinserted through the second hole 152 of the cover 15 and the dischargehole portion 112 of the upper housing 11. The outer wall of the union 51and the second hole 152 of the cover 15 are welded together over theentire circumference. As a result, the union 51 and the cover 15 areliquid-tightly kept.

The pulsation damper 16 is provided between a bottom portion of thecover 15 and the upper housing 11. The pulsation damper 16 is formed,for example, by joining peripheral portions of two diaphragms together,and gas at a predetermined pressure is sealed inside the pulsationdamper 16. A locking member 161 is provided in the vicinity of thebottom portion of the cover 15. A damper support portion 162 is providedon a side of the locking member 161 facing the upper housing 11. Thedamper support portion 162 sandwiches an outer edge portion of thepulsation damper 16 in cooperation with the locking member 161 and isfitted to the locking member 161, to thereby support the pulsationdamper 16. The pulsation damper 16 is capable of reducing fuel pressurepulsation with elastic deformation according to a change in the fuelpressure in the fuel gallery 100.

The plunger 20 is formed in a substantially columnar shape and made of ametal such as stainless steel. The plunger 20 includes a large diameterportion 201 and a small diameter portion 202. The small diameter portion202 has an outer diameter smaller than an outer diameter of the largediameter portion 201. The large diameter portion 201 and the smalldiameter portion 202 are coaxially integrated together. The plunger 20is provided such that the large diameter portion 201 is inserted intothe inside of the cylinder 13. The outer diameter of the large diameterportion 201 of the plunger 20 is formed to be substantially equal to aninner diameter of the cylinder 13 or slightly smaller than the innerdiameter of the cylinder 13. With the above configuration, the plunger20 is supported such that an outer wall of the large diameter portion201 slides on an inner wall of the cylinder 13 and is reciprocallymovable in the axial direction by the cylinder 13. A pressurizingchamber 103 is provided between inner walls of a cylinder portion and abottom portion of the cylinder 13 and an outer wall of an end portion ofthe large diameter portion 201 of the plunger 20. A volume of thepressurizing chamber 103 changes when the plunger 20 reciprocates in thecylinder 13.

In the present embodiment, a seal holder 21 is provided inside theholder support portion 14. The seal holder 21 is formed in a cylindricalshape and made of a metal such as stainless steel. The seal holder 21 isprovided so that an outer wall of the seal holder 21 is fitted to aninner wall of the holder support portion 14. The seal holder 21 isprovided so as to provide a substantially cylindrical clearance betweenthe inner wall of an end portion of the seal holder 21 opposite to thecylinder 13 and the outer wall of the small diameter portion 202 of theplunger 20. The seal 22 having the annular seal 22 between the innerwall of the seal holder 21 and the outer wall of the small diameterportion 202 of the plunger 20 includes a ring made of Teflon (registeredtrademark) on a radially inner side and a ring made of rubber on aradially outer side. A thickness of a fuel oil film around the smalldiameter portion 202 of the plunger 20 is adjusted by the seal 22, andleakage of the fuel to the engine is prevented. An oil seal 23 isprovided at an end portion of the seal holder 21 opposite from thecylinder 13. The thickness of the oil film around the small diameterportion 202 of the plunger 20 is adjusted by the oil seal 23, andleakage of oil is prevented.

A variable volume chamber 104 whose volume changes when the plunger 20reciprocates is provided between a stepped surface between the largediameter portion 201 and the small diameter portion 202 of the plunger20 and the seal 22. Further, in the present embodiment, the lowerhousing 12 has a hole portion 122 capable of communicating the fuelgallery 100 with the variable volume chamber 104. As a result, the fuelin the fuel gallery 100 can move back and forth relative to the variablevolume chamber 104 through the hole portion 122.

A substantially disc shaped spring seat 24 is provided at an end portionof the small diameter portion 202 of the plunger 20 opposite from thelarge diameter portion 201. An urging member 25 is provided between theseal holder 21 and the spring seat 24. The urging member 25 is formedof, for example, a coil spring, one end of which is in contact with thespring seat 24 and another end of which is in contact with the sealholder 21. The urging member 25 urges the plunger 20 through the springseat 24 in a direction away from the pressurizing chamber 103.

The high-pressure pump 1 is disposed in an engine in such a manner thatthe end portion of the small diameter portion 202 of the plunger 20opposite from the large diameter portion 201 is in contact with a cam 5of a camshaft which rotates in conjunction with a drive shaft of theengine (refer to FIG. 1). As a result, when the engine is rotating, theplunger 20 reciprocates in the axial direction with the rotation of thecam 5. At this time, the respective volumes of the pressurizing chamber103 and the variable volume chamber 104 are periodically changed. Theintake valve device 30 is provided in the intake passage 101 of theupper housing 11. The intake valve device 30 includes an intake valveseat portion 31, an intake valve member 32, a stopper 33, an intakevalve urging member 34, and the like.

The intake valve seat portion 31 is formed in a cylindrical shape andmade of a metal such as stainless steel. The intake valve seat portion31 is provided so that an outer wall of the intake valve seat portion 31is fitted to an inner wall of the upper housing 11 forming the intakehole portion 111. The intake valve seat portion 31 has an intake valveseat 311. The intake valve seat 311 has an annular shape and surrounds ahole in the center of a wall surface of the intake valve seat portion 31facing the pressurizing chamber 103.

The intake valve member 32 is made of a metal such as stainless steel.The intake valve member 32 has, for example, a substantially disc-shapedplate portion. The intake valve member 32 is provided such that a plateportion of the intake valve member 32 can contact the intake valve seat311 and can reciprocate within the intake passage 101.

The stopper 33 is formed in a bottomed cylindrical shape and made of ametal such as stainless steel. The stopper 33 is provided so that anouter wall of the stopper 33 is fitted to the inner wall of the upperhousing 11 forming the intake hole portion 111. The intake valve urgingmember 34 is provided between the plate portion of the intake valvemember 32 and the bottom portion of the stopper 33. The intake valveurging member 34 urges the intake valve member 32 toward the intakevalve seat 311.

In the present embodiment, the fuel is capable of flowing through a flowchannel provided in an outer edge portion of the stopper 33 between aspace between the intake valve seat portion 31 and the stopper 33 and aspace between the pressurizing chamber 103 and the stopper 33. Inaddition, the stopper 33 is, by contacting the intake valve member 32,capable of limiting the movement of the intake valve member 32 towardthe pressurizing chamber 103, that is, the movement in a valve openingdirection. Further, the stopper 33 has a bottom portion between theintake valve member 32 and the pressurizing chamber 103, thereby beingcapable of preventing the fuel from the pressurizing chamber 103 fromcolliding with the intake valve member 32.

The electromagnetic drive portion 40 is provided in the vicinity of theintake valve device 30. The electromagnetic drive portion 40 includes acylinder member 41, a nonmagnetic member 42, a needle 35, a needle guideportion 36, a needle urging member 37, a movable core 43, a fixed core44, a coil 45, a connector 46, cover members 47 and 48, and so on.

The cylinder member 41 is formed in a substantially cylindrical shapeand made of a magnetic material, for example. The cylinder member 41 isprovided so as to be inserted through the first hole 151 of the cover 15and the intake hole portion 111 of the upper housing 11. An outer wallof one end of the cylinder member 41 is fitted to an inner wall of theintake hole portion 111 of the upper housing 11. In this example, theintake valve seat portion 31 and the stopper 33 are sandwiched betweenone end of the cylinder member 41 and the inner wall forming the intakehole portion 111 of the upper housing 11. An end portion of the intakevalve seat portion 31 opposite from the intake valve seat 311 is locatedinside one end of the cylinder member 41.

The intake valve seat portion 31 has a hole portion 312 that connects aninner wall and an outer wall of the intake valve seat portion 31. Aplurality of the hole portions 312 are provided at regular intervals ina circumferential direction of the intake valve seat portion 31. In thepresent embodiment, two hole portions 312 are provided. In other words,the two hole portions 312 are provided to face each other across an axisof the intake valve seat portion 31. Further, the cylinder member 41 hasa groove portion 411 provided so as to be notched from one end of thecylinder member 41 toward the other end. Two groove portions 411 areprovided in total at positions corresponding to the hole portions 312 ofthe intake valve seat portion 31 one by one. Further, the upper housing11 has a hole portion 115 that connects an inner wall and an outer wallforming the intake hole portion 111. Two hole portions 115 are providedin total at positions corresponding to the groove portions 411 of thecylinder member 41 one by one. The fuel in the fuel gallery 100 can flowinto the inside of the intake valve seat portion 31 through the holeportion 115, the groove portion 411, and the hole portion 312. The fuelthat has flowed into the inside of the intake valve seat portion 31 canflow toward the pressurizing chamber 103 through between the intakevalve seat 311 and the intake valve member 32 and through the flowchannel of the stopper 33.

Further, the outer wall of the cylinder member 41 and the first hole 151of the cover 15 are welded over an entire circumference. As a result,the cylinder member 41 and the cover 15 are liquid-tightly kept. Thenonmagnetic member 42 is formed in a cylindrical shape and made of anonmagnetic material. The nonmagnetic member 42 is provided on the sideof the cylinder member 41 facing away from the upper housing 11 so as tobe coaxial with the cylinder member 41. The needle 35 is formed in a rodshape and made of, for example, a metal. The needle 35 is provided so asto reciprocate in the axial direction inside the cylinder member 41. Oneend of the needle 35 is capable of contacting the intake valve member32.

The needle guide portion 36 is provided so that an outer wall of theneedle guide portion 36 is fitted to an inner wall of the cylindermember 41. The needle guide portion 36 has a guide hole portion 361 inthe center. The guide hole portion 361 is formed to connect a wallsurface of the needle guide portion 36 facing the pressurizing chamber103 to a wall surface of the needle guide portion 36 facing away fromthe pressurizing chamber 103. A needle 35 is inserted through the guidehole portion 361. An inner diameter of the guide hole portion 361 issubstantially equal to an outer diameter of the needle 35 or slightlylarger than the outer diameter of the needle 35. The inner wall of theguide hole portion 361 and the outer wall of the needle 35 are slidableon each other. As a result, the needle guide portion 36 can guidemovement of the needle 35 in the axial direction.

The needle urging member 37 is formed of, for example, a coil spring,and is provided between the pressurizing chamber 103 and the needleguide portion 36. One end of the needle urging member 37 is in contactwith a protrusion portion annularly protruding from the needle 35radially outward, and another end of the needle urging member 37 isprovided so as to be in contact with the needle guide portion 36. Theneedle urging member 37 urges the needle 35 toward the pressurizingchamber 103. Therefore, the needle urging member 37 can urge the intakevalve member 32 toward the stopper 33 through the needle 35.

The movable core 43 is formed in a substantially cylindrical shape andmade of a magnetic material and press-fitted into the other end of theneedle 35. As a result, the movable core 43 can reciprocate in the axialdirection together with the needle 35. The fixed core 44 is formed in asolid cylindrical shape and made of a magnetic material and is providedon the side of the movable core 43 opposite from the pressurizingchamber 103. An end portion of the fixed core 44 facing the pressurizingchamber 103 is connected to the nonmagnetic member 42.

The coil 45 is formed in a substantially cylindrical shape and isprovided radially outward of the fixed core 44 and the nonmagneticmember 42. The periphery of the coil 45 is molded with a resin materialto form the connector 46. The connector 46 is insert-molded with aterminal 461. The terminal 461 and the coil 45 are electricallyconnected to each other.

The cover members 47 and 48 are made of a magnetic material. The covermember 47 is formed in a bottomed cylindrical shape, and accommodatesthe fixed core 44 and the coil 45 on an inner side of the cover member47, and a bottom portion of the cover member 47 contacts the fixed core44. The cover member 48 is formed in a plate shape and has a hole in thecenter. The cover member 48 is provided so as to close an opening end ofthe cover member 47 in a state in which the other end of the cylindermember 41 is inserted through the hole. In this example, the covermember 48 contacts the cover member 47 and the cylinder member 41.

The coil 45 generates a magnetic field by being supplied with electricpower from the outside through the terminal 461. When a magnetic fieldis generated in the coil 45, a magnetic circuit is formed in the fixedcore 44, the cover member 47, the cover member 48, the cylinder member41, and the movable core 43, and the movable core 43 is attracted towardthe fixed core 44 together with the needle 35. At this time, themagnetic circuit is formed so as to avoid the nonmagnetic member 42.

When no electric power is supplied to the coil 45, the intake valvemember 32 is urged toward the pressurizing chamber 103 by an urgingforce of the needle urging member 37 through the needle 35, and asurface of the intake valve member 32 facing the stopper 33 is incontact with the stopper 33. At this time, since the intake valve member32 is separated from the intake valve seat 311, the flow of fuel in theintake passage 101 and the intake hole 131 is permitted. On the otherhand, when the movable core 43 and the needle 35 are attracted towardthe fixed core 44 by supply of electric power to the coil 45, the intakevalve member 32 is urged by the urging force of the intake valve urgingmember 34 or the like to move away from the pressurizing chamber 103,and thereby contacts the intake valve seat 311. As a result, the fuelflow in the intake passage 101 and the intake hole 131 is blocked. Inthe manner described above, the intake valve device 30 can allow orinterrupt the flow of fuel in the intake passage 101 and the intake hole131 by the operation of the electromagnetic drive portion 40. In thepresent embodiment, the intake valve device 30 forms a so-callednormally open type valve device together with the electromagnetic driveportion 40.

Next, the discharge valve device 50 of the high-pressure pump 1according to the present embodiment will be described in detail. Asillustrated in FIG. 3, the discharge valve device 50 includes a valveseat portion 60, a discharge valve member 70, a discharge valve urgingmember 71, a relief valve member 80, a relief valve urging member 89, asupport portion 90, a fuel guide portion 84, and the like. The valveseat portion 60 is made of a metal such as stainless steel, and isprovided inside the union 51. The valve seat portion 60 includes a valveseat main body 61, a discharge valve passage 67, a relief valve passage68, a discharge valve seat 611, a relief valve seat 612, a valve seatcylinder portion 62, and a valve seat protrusion portion 63.

The valve seat main body 61 is provided in the discharge passage 102 soas to partition the discharge passage 102 into a first space 105 whichis a space positioned between the pressurizing chamber 103 and the valveseat main body 61 and a second space 106 which is a space positioned onthe opposite side of the valve seat main body 61 from the pressurizingchamber 103. The valve seat main body 61 is provided so that an outerwall of the valve seat main body 61 adjacent to the pressurizing chamber103 is in contact with the inner wall of the union 51. A cylindricalspace 107, which is a substantially cylindrical space, is providedbetween an outer wall of the valve seat main body 61 opposite from thepressurizing chamber 103 and the inner wall of the union 51.

The valve seat main body 61 has a recess portion 65 provided on thecenter of an end face of the valve seat main body 61 facing the firstspace 105 and recessed toward the second space 106. The recess portion65 has a bottom portion 651, a cylinder portion 652, and a taperedportion 653 (refer to FIG. 4). The bottom portion 651 is tapered so thata distance between an inner wall of the bottom portion 651 and an axisof the valve seat main body 61 decreases in a direction from the firstspace 105 toward the second space 106. The cylinder portion 652 isformed so as to extend from the outer edge portion of the bottom portion651 toward the pressurizing chamber 103. The cylinder portion 652 has asubstantially cylindrical inner wall. The tapered portion 653 is formedso as to extend toward the pressurizing chamber 103 from an end portionof the cylinder portion 652 which is opposite from the bottom portion651, and the tapered portion 653 has an opening on an end face of thevalve seat main body 61 facing the pressurizing chamber 103. The taperedportion 653 is tapered so that a distance between an inner wall of thetapered portion 653 and an axis of the valve seat main body 61 decreasesin a direction from the first space 105 toward the second space 106.

The valve seat main body 61 has a protrusion portion 64 formed so as toprotrude toward the second space 106 from the center of the end face ofthe valve seat main body 61 facing the second space 106. The protrusionportion 64 is tapered so that a distance between an outer wall of theprotrusion portion 64 and the axis decreases in a direction from thefirst space 105 toward the second space 106. The valve seat main body 61has a recess portion 66 formed on an end face of the protrusion portion64 facing away from the pressurizing chamber 103 and recessed toward thepressurizing chamber 103.

The discharge valve passage 67 is provided in the valve seat main body61 so as to connect the first space 105 to the second space 106. Anopening 671 of the discharge valve passage 67 in the first space 105 isprovided on the radially outward of the recess portion 65. An opening672 of the discharge valve passage 67 in the second space 106 isprovided at the bottom portion of the recess portion 66. In the presentembodiment, two discharge valve passages 67 are provided in the valveseat main body 61. Further, the two discharge valve passages 67 areformed such that the axis of the valve seat main body 61 is interposedtherebetween, and the discharge valve passages 67 are inclined withrespect to the axis.

The relief valve passage 68 is provided in the valve seat main body 61so as to connect the second space 106 to the first space 105 withoutcommunicating with the discharge valve passage 67. In the presentembodiment, the relief valve passage 68 has a first passage 681 and asecond passage 682. The first passage 681 extends orthogonally to theaxis of the valve seat main body 61, and both end portions of the firstpassage 681 open to an outer wall of the valve seat main body 61. As aresult, the first passage 681 communicates with the cylindrical space107. The second passage 682 extends along the axis of the valve seatmain body 61, and one end of the second passage 682 is connected to thecenter of the first passage 681. In the second passage 682, the opening683 at the other end is provided in the bottom portion 651 of the recessportion 65 (refer to FIG. 4). The discharge valve seat 611 is annularlyformed at the outer edge portion of the recess portion 66. In otherwords, the discharge valve seat 611 has an annular shape and surroundsthe opening 672 of the discharge valve passage 67 of the valve seat mainbody 61 in the second space 106.

The relief valve seat 612 has an annular shape and surrounds the opening683 of the relief valve passage 68 of the valve seat main body 61 in thefirst space 105. In this example, the relief valve seat 612 is taperedso as to decrease in distance from the axis of the relief valve seat 612in a direction from the first space 105 toward the second space 106(refer to FIG. 4). The valve seat cylinder portion 62 is formed so as toextend in a cylindrical shape toward the pressurizing chamber 103 froman outer edge portion of an end face of the valve seat main body 61facing the first space 105. In this example, an outer wall of the valveseat cylinder portion 62 is in contact with an inner wall of the union51.

The valve seat protrusion portion 63 has an annular shape and protrudesradially outward from an end portion of the valve seat cylinder portion62 opposite from the valve seat main body 61. In this example, the valveseat protrusion portion 63 is sandwiched between the step portion 114 ofthe upper housing 11 and the end portion of the union 51 facing thepressurizing chamber 103. As a result, a relative movement of the valveseat portion 60 relative to the upper housing 11 in the axial directionis limited.

The discharge valve member 70 is formed in a substantially disk shapeand made of a metal such as stainless steel. The discharge valve member70 is provided in the second space 106 so as to be capable of contactingthe discharge valve seat 611, and separates from the discharge valveseat 611 or contacts the discharge valve seat 611 to open or close thedischarge valve passage 67.

In the present embodiment, the discharge valve device 50 furtherincludes a holder 72. The holder 72 is made of a metal such as stainlesssteel, and is disposed in the second space 106 inside the union 51. Theholder 72 includes a holder bottom portion 73, a holder cylinder portion74, and a holder protrusion portion 75.

The holder bottom portion 73 is formed in a substantially disk shape,and has a hole portion 731 penetrating in a thickness direction in thecenter of the holder bottom portion 73. The holder cylinder portion 74is formed so as to extend cylindrically from an outer edge portion ofthe holder bottom portion 73 toward the pressurizing chamber 103. Acylindrical space 108 which is a substantially cylindrical space isprovided between an outer wall of the holder cylinder portion 74 and aninner wall of the union 51. The protrusion portion 64 of the valve seatmain body 61 and the discharge valve member 70 are located inside an endportion of the holder cylinder portion 74 opposite from the holderbottom portion 73. An inner wall of an end portion of the holdercylinder portion 74 opposite from the holder bottom portion 73 istapered so as to correspond to a shape of the outer wall of theprotrusion portion 64. A cylindrical space 109, which is a cylindricalspace, is provided between the outer wall of the protrusion portion 64and the inner wall of the holder cylinder portion 74. The cylindricalspace 109 and the cylindrical space 107 communicate with each otherthrough a space between the holder 72 and the valve seat main body 61(refer to FIG. 3).

The holder cylinder portion 74 has multiple hole portions 741 providedso as to connect an inner wall and an outer wall of the holder cylinderportion 74 in the vicinity of the end portion opposite from the holderbottom portion 73. As a result, the hole portion 741 communicates withthe cylindrical space 108 and the cylindrical space 109. In the presentembodiment, four hole portions 741 are provided at four intervals in thecircumferential direction of the holder cylinder portion 74, forexample. With the above configuration, the relief valve passage 68communicates with the cylindrical space 108 through the cylindricalspace 107, the cylindrical space 109, and the hole portion 741. Theholder cylinder portion 74 has a step portion 742 on an inner wall ofthe hole portion 741 behind which the holder bottom portion 73 ispositioned. The step portion 742 is formed in a substantially annularshape so that the outer edge portion of the discharge valve member 70can contact the step portion 742.

The holder protrusion portion 75 is annularly formed so as to protruderadially outward from the end portion of the holder cylinder portion 74opposite from the holder bottom portion 73. The holder 72 is provided sothat the holder protrusion portion 75 is fitted to the inner wall of theunion 51 and is in contact with the step portion 52 of the union 51. Asa result, relative movement of the holder 72 in the axial direction withrespect to the union 51 is restricted.

The discharge valve urging member 71 is, for example, a coil spring, andis provided on a side of the discharge valve member 70 opposite from thevalve seat portion 60. The discharge valve urging member 71 is providedinside the holder cylinder portion 74 such that one end of the dischargevalve urging member 71 is in contact with the discharge valve member 70and another end of the discharge valve urging member 71 is in contactwith the holder bottom portion 73 of the holder 72. The discharge valveurging member 71 urges the discharge valve member 70 toward thedischarge valve seat 611. As a result, the discharge valve member 70 ispressed against the discharge valve seat 611.

The discharge valve member 70 is provided so as to reciprocate insidethe holder 72 in the axial direction. The discharge valve member 70contacts the step portion 742 of the holder 72 to limit the movementtoward the holder bottom portion 73. Therefore, the discharge valvemember 70 is movable in the axial direction between the discharge valveseat 611 and the step portion 742.

The relief valve member 80 is made of a metal such as stainless steel,for example. In the present embodiment, a hardness of the relief valvemember 80 is set to be equal to the hardness of the valve seat portion60. The relief valve member 80 includes a relief valve main body 81, arelief valve seat portion 82, and a valve member protrusion portion 83.

The relief valve main body 81 is formed in a rod shape, morespecifically, a substantially columnar shape. The relief valve member 80is disposed in the first space 105 so as to be arranged that the endportion 811 which is one end of the relief valve main body 81 is locatedinside the recess portion 65 of the valve seat main body 61 and theother end of the relief valve main body 81 faces the pressurizingchamber 103 In the first space 105. A large diameter portion 812 isformed on a side of the end portion 811 of the relief valve main body 81facing the pressurizing chamber 103. The end portion 811 and the largediameter portion 812 are formed in a substantially columnar shape. Thelarge diameter portion 812 has an outer diameter set to be larger thanthe outer diameter of the end portion 811 (refer to FIG. 4). An outerdiameter of the end portion 811 is slightly smaller than an innerdiameter of the cylinder portion 652 of the recess portion 65. For thatreason, a substantially cylindrical gap is provided between the endportion 811 and the cylinder portion 652.

The relief valve seat portion 82 is integrally formed with the reliefvalve main body 81 at one axial end (first end) (end portion 811) of therelief valve main body 81 so as to be capable of contacting the reliefvalve seat 612. More specifically, the relief valve seat portion 82 hasa substantially columnar shape and projects from the center of the endportion 811 of the relief valve main body 81 toward the second space106. A side of the relief valve seat portion 82 facing the second space106 includes a first tapered surface 821 and a second tapered surface822. The first tapered surface 821 is tapered so as to decrease indistance from the axis of the relief valve seat portion 82 along adirection from the first space 105 toward the second space 106. Thesecond tapered surface 822 is formed on a side of the first taperedsurface 821 facing the second space 106 so as to be connected to thefirst tapered surface 821. The second tapered surface 822 is tapered soas to decrease in distance from the axis of the relief valve seatportion 82 in the direction from the first space 105 toward the secondspace 106. In this example, an angle formed by a virtual straight lineextending along the first tapered surface 821 and the axis of the reliefvalve seat portion 82 is smaller than an angle formed by a virtualstraight line extending along the second tapered surface 822 and theaxis of the relief valve seat portion 82 (refer to FIG. 4). Therefore,an edge is formed between (boundary) the first tapered surface 821 andthe second tapered surface 822.

In the present embodiment, the angle formed by the virtual straight lineextending along the first tapered surface 821 and the axis of the reliefvalve seat portion 82 is set to be substantially equal to an angleformed by the virtual straight line extending along the relief valveseat 612 and the axis of the relief valve seat portion 612. For thatreason, in the relief valve member 80, the first tapered surface 821 cancontact the relief valve seat 612 by surface contact. When the firsttapered surface 821 and the relief valve seat 612 come in surfacecontact with each other, the relief valve seat portion 82 and the reliefvalve seat 612 are in a coaxial relationship. In this manner, the reliefvalve member 80 and the relief valve seat 612 are aligned by the firsttapered surface 821 and the relief valve seat 612.

As shown in FIG. 4, an intermediate chamber 654 which is an annularspace is provided between the relief valve seat portion 82 and thebottom portion 651 and the cylinder portion 652 of the recess portion65. The valve member protrusion portion 83 has an annular shape andprojects radially outward from an end of the large diameter portion 812of the relief valve main body 81 facing the pressurizing chamber 103.The relief valve member 80 is provided in the first space 105 so as tobe reciprocable in an axial direction of the relief valve main body 81.

In the present embodiment, the opening 671 of the discharge valvepassage 67 the first space 105 is provided outside of a virtualcylindrical surface C1 that passes through an outermost portion (i.e.outer wall of the valve member protrusion portion 83) of an outer wallof the relief valve member 80 and extends in a cylindrical shape in theaxial direction of the relief valve main body 81 (refer to FIG. 3).

The relief valve urging member 89 is formed of, for example, a coilspring, and the relief valve main body 81 is inserted through the insideof the relief valve urging member 89. In other words, the relief valveurging member 89 is provided on a radially outer side of the reliefvalve main body 81. One end of the relief valve urging member 89 is incontact with a wall surface of the valve member protrusion portion 83facing the pressurizing chamber 103.

The support portion 90 is formed of a metal such as stainless steel, andis provided in the first space 105. In the present embodiment, ahardness of the support portion 90 is set to be lower than the hardnessof the valve seat portion 60 and the relief valve member 80. The supportportion 90 includes a support main body 91, a guide hole portion 94, asupport cylinder portion 92, and a spring seat member 93.

The support main body 91 is formed in a substantially disc shape andprovided in the first space 105. The guide hole portion 94 is formed soas to penetrate through a center of the support main body 91 in a platethickness direction. In other words, the guide hole portion 94 is formedto connect a surface of the support main body 91 facing the pressurizingchamber 103 and a surface of the support main body 91 facing the valveseat portion 60. The relief valve main body 81 of the relief valvemember 80 is inserted through the guide hole portion 94. The guide holeportion 94 has an inner diameter substantially equal to an outerdiameter of the other end of the relief valve main body 81, i.e. anouter diameter of an end portion of the relief valve main body 81 facingthe pressurizing chamber 103, or somewhat larger than an outer diameterof the end portion of the relief valve main body 81 facing thepressurizing chamber 103. Therefore, the inner wall of the guide holeportion 94 can slide with the outer wall of the other axial end (secondend) of the relief valve main body 81.

As shown in FIG. 5, the guide hole portion 94 has chamfered portions 941and 942. The chamfered portion 941 is formed on a side of the guide holeportion 94 facing the pressurizing chamber 103. The chamfered portion942 is formed between the valve seat portion 60 and the guide holeportion 94. Each of the chamfered portions 941 and 942 has a chamferangle of 45 degrees. In the present embodiment, a chamfer size of thechamfered portion 941 is set to, for example, C0.1 or less. The size ofthe chamfered portion 942 is set to be larger than the chamfered portion941.

The support cylinder portion 92 is formed so as to extend substantiallyin a cylindrical shape from the outer edge portion of the support mainbody 91 toward the valve seat portion 60. The support portion 90 isprovided such that an outer wall of an end portion of the supportcylinder portion 92 opposite from the support main body 91 is fitted toan inner wall of the valve seat cylinder portion 62. As a result, thesupport portion 90 is provided so as not to be movable relative to thevalve seat portion 60, and supports the relief valve member 80 by thesupport main body 91 so that the relief valve member 80 can reciprocatein the axial direction. In this manner, the support main body 91 of thesupport portion 90 slidably supports the outer wall of the relief valvemain body 81 so as to guide the reciprocating movement of the reliefvalve member 80 in the axial direction.

In the present embodiment, since the hardness of the support portion 90is set to be lower than the hardness of the valve seat portion 60, thesupport cylinder portion 92 can be easily fitted to the inner wall ofthe valve seat cylinder portion 62. A cylindrical space 110, which is asubstantially cylindrical space, is provided between an outer wall ofthe end portion of the support cylinder portion 92 adjacent to thesupport main body 91 and the inner wall of the upper housing 11 formingthe discharge hole portion 112.

The support cylinder portion 92 has multiple hole portions 921 providedso as to connect the inner wall and the outer wall of the supportcylinder portion 92. As a result, the hole portion 921 communicates withthe space inside the support cylinder portion 92 and the cylindricalspace 110. In the present embodiment, for example, four hole portions921 are provided at regular intervals in the circumferential directionof the support cylinder portion 92.

The spring seat member 93 is formed in a substantially disk shapeseparately from the support main body 91 and the support cylinderportion 92. The spring seat member 93 is provided on a side of thesupport main body 91 facing the valve seat portion 60. The spring seatmember 93 has a hole portion penetrating in the plate thicknessdirection at the center, and an end portion of the relief valve mainbody 81 facing the pressurizing chamber 103 is inserted into the holeportion.

The other end of the relief valve urging member 89 is in contact with asurface of the spring seat member 93 facing the valve seat portion 60.The relief valve urging member 89 presses the spring seat member 93against the support main body 91 and urges the relief valve member 80toward the relief valve seat 612. As a result, the first tapered surface821 of the relief valve seat portion 82 is pressed against the reliefvalve seat 612.

As shown in FIG. 5, the fuel guide portion 84 is provided at the otherend of the relief valve main body 81, i.e. the end portion facing thepressurizing chamber 103, and is integrated with the relief valve mainbody 81. The fuel guide portion 84 includes a first specific shapeportion 841, a second specific shape portion 842, a third specific shapeportion 843, and a fourth specific shape portion 844. The first specificshape portion 841, the third specific shape portion 843, the secondspecific shape portion 842, and the fourth specific shape portion 844are integrated together so as to be arranged seamlessly in said order inthe direction from the pressurizing chamber 103 toward the valve seatportion 60.

In FIG. 5, in order to avoid complication of the drawing,cross-sectional hatching of the relief valve main body 81 and the fuelguide portion 84 is omitted. Further, a boundary between the firstspecific shape portion 841 and the third specific shape portion 843, anda boundary between the second specific shape portion 842 and the fourthspecific shape portion 844 are indicated by two-dot chain lines.

The first specific shape portion 841 is formed such that the outer wallof the first specific shape portion 841 increases in its distance fromthe axis Ax1 of the fuel guide portion 84 along the direction from thepressurizing chamber 103 toward the valve seat portion 60. The secondspecific shape portion 842 is formed between the valve seat portion 60and the first specific shape portion 841 so that the outer wall of thesecond specific shape portion 842 increases in its distance from theaxis Ax1 along the direction from the pressurizing chamber 103 towardthe valve seat portion 60. The first specific shape portion 841 and thesecond specific shape portion 842 are formed so that a shape of theouter wall of each shape portion is linear in a cross sectional planewhich is a virtual plane including the axis Ax1. In other words, thefirst specific shape portion 841 and the second specific shape portion842 are tapered so that a diameter reduction ratio, which is a ratio atwhich the outer diameter decreases according to a positional change inthe direction of the axis Ax1, is kept constant.

The fuel guide portion 84 is formed so that a first angle θ1 which is anangle between a first virtual straight line L1 extending along the outerwall of the first specific shape portion 841 and the axis Ax1 isdifferent from a second angle θ2 which is an angle between a secondvirtual straight line L2 extending along the outer wall of the secondspecific shape portion 842 and the axis Ax1. In the present embodiment,the first angle θ1 is set to, for example, approximately 5 degrees. Thesecond angle θ2 is set to, for example, approximately 65 degrees.

The third specific shape portion 843 is formed to connect the firstspecific shape portion 841 to the second specific shape portion 842. Inthe present embodiment, the third specific shape portion 843 is formedso that a shape of the outer wall in the cross sectional plane which isthe virtual plane including the axis Ax1 is curved and recessed towardthe axis Ax1. In other words, the third specific shape portion 843 isformed such that the diameter reduction ratio in the direction of theaxis Ax1 decreases along the direction from the valve seat portion 60toward the pressurizing chamber 103.

The fourth specific shape portion 844 is formed to connect the secondspecific shape portion 842 to an end portion of the relief valve mainbody 81 facing the pressurizing chamber 103. The fourth specific shapeportion 844 is formed so that a shape of the outer wall in the crosssectional plane which is the virtual plane including the axis Ax1 iscurved and recessed away from the axis Ax1. In other words, the fourthspecific shape portion 844 is formed such that the diameter reductionratio in the direction of the axis Ax1 increases along the directionfrom the valve seat portion 60 toward the pressurizing chamber 103.

In the present embodiment, an outer diameter of an end portion of thefourth specific shape portion 844 facing the relief valve main body 81is set to be equal to the outer diameter of the end portion of therelief valve main body 81 facing the pressurizing chamber 103.Therefore, the outer diameter of the end portion of the fourth specificshape portion 844 facing the relief valve main body 81 is smaller thanan inner diameter of the guide hole portion 94. In other words, the fuelguide portion 84 is formed such that a largest outer diameter is smallerthan an inner diameter of the guide hole portion 94. With the aboveconfiguration, the fuel flowing from the pressurizing chamber 103 to thevalve seat portion 60 is guided so as to flow in the direction radiallyoutward of the relief valve main body 81 when flowing along the outerwall of the fuel guide portion 84 (refer to FIG. 5). As described above,the fuel guide portion 84 can guide the fuel so that the fuel flows inthe direction radially outward of the relief valve main body 81 on theway from the pressurizing chamber 103 to the valve seat portion 60.

When a pressure of the fuel in the first space 105 is higher than atotal of a pressure of the fuel in the second space 106 and an urgingforce of the discharge valve urging member 71 (the valve openingpressure of the discharge valve member 70), the discharge valve member70 is separated from the discharge valve seat 611 and opened. At thistime, the pressurizing chamber 103 communicates with a space inside theend portion of the union 51 adjacent to the pipe 6 through the dischargehole 132, the cylindrical space 110, the hole portion 921, inner spacesof the support cylinder portion 92 and the valve seat cylinder portion62, the discharge valve passage 67, the recess portion 66, the holeportion 741, and the cylindrical space 108. As a result, the fuel fromthe pressurizing chamber 103, that is, the fuel in the first space 105is discharged toward the pipe 6, i.e. to the second space 106, throughthe discharge valve seat 611. The valve opening pressure of thedischarge valve member 70 can be set by adjusting the urging force ofthe discharge valve urging member 71.

On the other hand, when a pressure of the fuel in the second space 106is higher than a total of the pressure of the fuel in the first space105 and an urging force of the relief valve urging member 89 (the valveopening pressure of the relief valve member 80), the relief valve member80 is separated from the relief valve seat 612 and opened. At this time,the space inside the end portion of the union 51 adjacent to the pipe 6communicates with the pressurizing chamber 103 through the cylindricalspace 108, the hole portion 741, the cylindrical space 109, thecylindrical space 107, the first passage 681 of the relief valve passage68, the second passage 682, the recess portion 65, the spaces inside thevalve seat cylinder portion 62 and the support cylinder portion 92, thehole portion 921, the cylindrical space 110, and the discharge hole 132.As a result, the fuel on the pipe 6, that is, the fuel in the secondspace 106 is returned toward the pressurizing chamber 103, i.e. to thefirst space 105, through the relief valve seat 612. As a result, thepressure of the fuel in the second space 106 can be prevented fromincreasing abnormally. The valve opening pressure of the relief valvemember 80 can be set by adjusting the urging force of the relief valveurging member 89.

Further, in the present embodiment, the urging force of the relief valveurging member 89 is set to be larger than the extent that the endportion 811 of the relief valve member 80 does not come out of therecess portion 65. For that reason, the end portion 811 of the reliefvalve member 80 is prevented from coming out of the recess portion 65.As described above, the discharge valve device 50 according to thepresent embodiment is a relief valve integrated discharge valve devicehaving both of a function as the discharge valve and a function as therelief valve.

Next, the operation of the high-pressure pump 1 according to the presentembodiment will be described with reference to FIG. 2.

“Intake Process”

When the supply of an electric power to the coil 45 of theelectromagnetic drive portion 40 is stopped, the intake valve member 32is urged toward the pressurizing chamber 103 by the needle urging member37 and the needle 35. Therefore, the intake valve member 32 is separatedfrom the intake valve seat 311, that is, is opened. In this state, whenthe plunger 20 moves toward the cam 5, a volume of the pressurizingchamber 103 increases, and the fuel in the intake passage 101 issuctioned into the pressurizing chamber 103.

“Metering Process”

When the plunger 20 moves in a direction away from the cam 5 in a statein which the intake valve member 32 is opened, the volume of thepressurizing chamber 103 decreases, and the fuel in the pressurizingchamber 103 returns to the fuel gallery 100 of the intake passage 101.When the electric power is supplied to the coil 45 during a meteringprocess, the movable core 43 is attracted toward the fixed core 44together with the needle 35, and the intake valve member 32 contacts andcloses the intake valve seat 311. When the plunger 20 moves in thedirection away from the cam 5, the intake valve member 32 is closed toblock a communication between the pressurizing chamber 103 and the fuelgallery 100 of the intake passage 101, thereby adjusting the amount offuel returned from the pressurizing chamber 103 toward the fuel gallery100 of the intake passage 101. As a result, the amount of fuelpressurized in the pressurizing chamber 103 is determined. The intakevalve member 32 is closed, to thereby terminate the metering process ofreturning the fuel from the pressurizing chamber 103 to the fuel gallery100 of the intake passage 101.

“Pressurizing Process”

When the plunger 20 further moves in the direction away from the cam 5in a state where the intake valve member 32 is closed, a volume of thepressurizing chamber 103 decreases, and the fuel in the pressurizingchamber 103 is compressed and pressurized. When the pressure of the fuelin the pressurizing chamber 103 becomes equal to or higher than a valveopening pressure of the discharge valve member 70, the discharge valvemember 70 opens and the fuel is discharged from the pressurizing chamber103 toward the pipe 6, i.e. to the second space 106.

When the supply of power to the coil 45 is stopped and the plunger 20moves toward the cam 5, the intake valve member 32 opens again. As aresult, the pressurizing process for pressurizing the fuel is completed,and the intake process of sucking the fuel from the fuel gallery 100 ofthe intake passage 101 to the pressurizing chamber 103 is restarted.

With the repetition of the “intake process”, “metering process” and“pressurizing process” described above, the high-pressure pump 1pressurizes and discharges the sucked fuel in the fuel tank 2 andsupplies the fuel to the fuel rail 7. The supply amount of fuel from thehigh-pressure pump 1 to the fuel rail 7 is adjusted by controlling asupply timing of the electric power to the coil 45 of theelectromagnetic drive portion 40 and the like.

For example, when a state in which the supply of the electric power tothe coil 45 is stopped is continued for a predetermined period of time,the intake valve member 32 maintains the valve open state. Therefore,the fuel is not pressurized in the pressurizing chamber 103, and thefuel is not supplied from the high-pressure pump 1 to the fuel rail 7.Even when the intake valve member 32 is maintained in the valve openstate due to some cause, such as the fixing of the intake valve member32, the fuel is not pressurized in the pressurizing chamber 103, and thefuel is not supplied from the high-pressure pump 1 to the fuel rail 7.

On the other hand, for example, when the supply of the electric power tothe coil 45 continues for the predetermined period of time, the intakevalve member 32 is closed in the pressurizing process. Therefore, thefuel is pressurized in the pressurizing chamber 103, supplied from thehigh-pressure pump 1 to the rail 7, and the pressure of the fuel in thesecond space 106, the pipe 6, and the fuel rail 7 increases. Even whenthe intake valve member 32 is maintained in the valve close state due tosome reason such as fixing of the intake valve member 32, the fuel ispressurized in the pressurizing chamber 103 and supplied from thehigh-pressure pump 1 to the fuel rail 7, and the pressure of the fuel inthe second space 106, the pipe 6, and the fuel rail 7 increases.

Next, the operation of the discharge valve device 50 of thehigh-pressure pump 1 according to the present embodiment will bedescribed. As shown in FIG. 6, when the pressure of the fuel in thefirst space 105 becomes larger than the valve opening pressure of thedischarge valve member 70, the discharge valve member 70 separates fromthe discharge valve seat 611 and opens. At this time, the fuel in thepressurizing chamber 103 can flow into the space inside the end portionof the union 51 adjacent to the pipe 6 through the discharge hole 132,the cylindrical space 110, the hole portion 921, the spaces inside thesupport cylinder portion 92 and the valve seat cylinder portion 62, thedischarge valve passage 67, the recess portion 66, the hole portion 741,and the cylindrical space 108.

In the present embodiment, the support main body 91 of the supportportion 90 slidably supports the outer wall of the relief valve mainbody 81 so as to guide the movement of the relief valve member 80 in theaxial direction. For that reason, even if the fuel discharged from thepressurizing chamber 103 flows around the relief valve member 80, therelief valve seat portion 82 of the relief valve member 80 is preventedfrom relatively moving or oscillating in the radial direction withrespect to the relief valve seat 612. As a result, wear of the reliefvalve seat 612 or the relief valve seat portion 82 can be reduced.

In the present embodiment, when the discharge valve member 70 is open,the fuel flowing from the pressurizing chamber 103 to the valve seatportion 60 in the vicinity of the fuel guide portion 84 of the reliefvalve member 80 is guided to flow in the radially outward direction ofthe relief valve main body 81 by the fuel guide portion 84 (refer toFIG. 5). As a result, the fuel can be prevented from entering a spacebetween the guide hole portion 94 of the support portion 90 and therelief valve main body 81. For that reason, the cavitation erosion canbe prevented from occurring between the guide hole portion 94 and therelief valve main body 81, and erosion of the guide hole portion 94 ofthe support portion 90 can be reduced.

Further, in the present embodiment, a size of the chamfered portion 941of the guide hole portion 94 facing the pressurizing chamber 103 is setto be small (C0.1 or less). For that reason, the fuel can be moreeffectively prevented from entering the space between the guide holeportion 94 of the support portion 90 and the relief valve main body 81.

Further, in the present embodiment, the relief valve seat portion 82 isformed integrally with the relief valve main body 81. For that reason,the relief valve seat portion 82 and the relief valve main body 81 donot move relative to each other. Therefore, the position of the reliefvalve seat portion 82 is stabilized, for example, as compared with aconfiguration in which the relief valve main body 81 and the reliefvalve seat portion 82 are formed separately from each other.

In the present embodiment, the opening 671 of the discharge valvepassage 67 in the first space 105 is provided outside of a virtualcylindrical surface C1 that passes through an outermost portion (outerwall of the valve member protrusion portion 83) of an outer wall of therelief valve member 80 and extends in a cylindrical shape in the axialdirection of the relief valve main body 81. For that reason, when thefuel is discharged from the pressurizing chamber 103, the fuel aroundthe relief valve main body 81 can smoothly flow into the discharge valvepassage 67 without being blocked by the valve member protrusion portion83 of the relief valve member 80.

As shown in FIG. 7, when the pressure of the fuel in the second space106 becomes larger than the valve opening pressure of the relief valvemember 80, the relief valve member 80 separates from the relief valveseat 612 and opens. At this time, the fuel in the space inside the endportion of the union 51 adjacent to the pipe 6 can flow toward thepressurizing chamber 103 through the cylindrical space 108, the holeportion 741, the cylindrical space 109, the cylindrical space 107, thefirst passage 681 of the relief valve passage 68, the second passage682, the recess portion 65, the spaces inside the valve seat cylinderportion 62 and the support cylinder portion 92, the hole portion 921,the cylindrical space 110, and the discharge hole 132.

In the present embodiment, the support main body 91 of the supportportion 90 slidably supports the outer wall of the relief valve mainbody 81 so as to guide the reciprocating movement of the relief valvemember 80 in the axial direction. As a result, when the relief valvemember 80 opens, the movement of the relief valve member 80 toward thepressurizing chamber 103 is stabilized.

Further, in the present embodiment, when the relief valve seat portion82 is separated from the relief valve seat 612, the fuel in the reliefvalve passage 68 flows into the intermediate chamber 654 (refer to FIG.4). As a result, the pressure in the intermediate chamber 654 quicklyrises, and the relief valve member 80 can be promptly moved toward thepressurizing chamber 103. The fuel in the intermediate chamber 654 flowsbetween the cylinder portion 652 and the tapered portion 653 of therecess portion 65 and the end portion 811 and the large diameter portion812 of the relief valve main body 81 toward the pressurizing chamber103.

As described above, (1) in the present embodiment, the pump body 10includes the pressurizing chamber 103 for pressurizing the fuel and thedischarge passage 102 through which the fuel pressurized by anddischarged from the pressurizing chamber 103 flows. The valve seatportion 60 includes the valve seat main body 61, a discharge valvepassage 67, the relief valve passage 68, the discharge valve seat 611,and the relief valve seat 612.

The valve seat main body 61 is provided in the discharge passage 102 soas to partition the discharge passage 102 into a first space 105 whichis a space positioned between the valve seat main body 61 and thepressurizing chamber 103 and a second space 106 which is a spacepositioned on the opposite side of the valve seat main body 61 from thepressurizing chamber 103. The discharge valve passage 67 is provided inthe valve seat main body 61 so as to connect the first space 105 to thesecond space 106. The relief valve passage 68 is provided in the valveseat main body 61 so as to connect the second space 106 to the firstspace 105 and not to communicate with the discharge valve passage 67.The discharge valve seat 611 has an annular shape and surrounds theopening 672 of the discharge valve passage 67 of the valve seat mainbody 61 in the second space 106. The relief valve seat 612 has anannular shape and surrounds the opening 683 of the relief valve passage68 of the valve seat main body 61 in the first space 105.

The discharge valve member 70 is provided in the second space 106 so asto be capable of contacting the discharge valve seat 611, and separatesfrom the discharge valve seat 611 or contacts the discharge valve seat611 to open or close the discharge valve passage 67. The discharge valveurging member 71 urges the discharge valve member 70 toward thedischarge valve seat 611. The relief valve member 80 includes a reliefvalve main body 81 and a relief valve seat portion 82.

The relief valve main body 81 is formed in a rod shape. The relief valveseat portion 82 is formed integrally with the relief valve main body 81at one end of the relief valve main body 81 so as to be capable ofcontacting the relief valve seat 612. The relief valve member 80 isprovided in the first space 105 so as to reciprocate in the axialdirection. The relief valve urging member 89 urges the relief valvemember 80 toward the relief valve seat 612. The support portion 90includes the support main body 91 and the guide hole portion 94.

The support main body 91 is disposed in the first space 105. The guidehole portion 94 connects a surface of the support main body 91 facingthe pressurizing chamber 103 and a surface of the support main body 91facing the valve seat portion 60, and the relief valve main body 81 isinserted into the guide hole portion 94. The guide hole portion 94 ofthe support portion 90 slidably supports the outer wall of the reliefvalve main body 81 so as to guide the reciprocating movement of therelief valve member 80 in the axial direction. The fuel guide portion 84is provided at an end portion of the relief valve main body 81 facingthe pressurizing chamber 103 and can guide the fuel so that the fuelflows in the direction radially outward of the relief valve main body 81on the way from the pressurizing chamber 103 to the valve seat portion60.

In the present embodiment, the guide hole portion 94 of the supportportion 90 slidably supports the outer wall of the relief valve mainbody 81 so as to guide the reciprocating movement of the relief valvemember 80 in the axial direction. For that reason, even if the fueldischarged from the pressurizing chamber 103 in the high-pressure pump 1flows around the relief valve member 80, the relief valve seat portion85 of the relief valve member 80 is prevented from relatively moving oroscillating in the radial direction with respect to the relief valveseat 612. As a result, wear of the relief valve seat 612 or the reliefvalve seat portion 85 can be reduced. Therefore, a change over time inthe valve opening pressure of the relief valve member 80 can be reduced.

In the present embodiment, for example, when the fuel is discharged fromthe pressurizing chamber 103, the fuel passing by the fuel guide portion84 from the pressurizing chamber 103 toward the valve seat portion 60flows in the direction radially outward of the relief valve main body81. For that reason, the fuel can be prevented from entering a spacebetween the inner wall of the guide hole portion 94 and the outer wallof the relief valve main body 81. As a result, cavitation erosion occursbetween the guide hole portion 94 and the relief valve main body 81, andthe guide hole portion 94 or the relief valve main body 81 can beprevented from being eroded. As a result, the backlash between the guidehole portion 94 and the relief valve main body 81 can be prevented fromincreasing even after a long period of time, and the relief valve seat612 or the relief valve seat portion 85 can be prevented from beingworn. As a result, according to the present embodiment, a change overtime in the valve opening pressure of the relief valve member 80 can bereduced for a long period of time.

(2) In the present embodiment, the support portion 90 slidably supportsthe outer wall of the other end side of the relief valve main body 81,that is, the end portion facing the pressurizing chamber 103 by theguide hole portion 94. In other words, the fuel guide portion 84 and theguide hole portion 94 are disposed at relatively close positions. In thepresent embodiment, the fuel flowing from the pressurizing chamber 103toward the valve seat portion 60 is guided by the fuel guide portion 84to flow in the direction radially outward of the relief valve main body81. Therefore, even if the fuel guide portion 84 and the guide holeportion 94 are disposed close to each other, the fuel can be effectivelyprevented from entering a space between the guide hole portion 94 andthe relief valve main body 81.

Further, with the configuration in which the guide hole portion 94supports the outer wall of the relief valve main body 81 on the otherend, the axis of the relief valve member 80 can be effectively preventedfrom being inclined during the reciprocating movement of the reliefvalve member 80. Since a sliding portion between the inner wall of thesupport portion 90 and the outer wall of the relief valve main body 81is located at a position far from the relief valve seat 612, the innerwall of the support portion 90 and the outer wall of the relief valvemain body 81 are abraded by sliding. Even if abrasion powder isgenerated, the abrasion powder can be prevented from being caughtbetween the relief valve seat 612 and the relief valve seat portion 82.

(3) In the present embodiment, the fuel guide portion 84 includes thefirst specific shape portion 841 whose outer wall increases in itsdistance from the axis Ax1 of the fuel guide portion 84 in the directionfrom the pressurizing chamber 103 toward the valve seat portion 60, andthe second specific shape portion 842 which is formed between the valveseat portion 60 and the first specific shape portion 841 so that anouter wall of the second specific shape portion 842 increases in itsdistance from the axis Ax1 in the direction from the pressurizingchamber 103 toward the valve seat portion 60. This exemplifies aspecific configuration of the fuel guide portion 84 according to thepresent embodiment. With the above configuration, the fuel flowing fromthe pressurizing chamber 103 toward the valve seat portion 60 can beeffectively guided so as to flow in the direction radially outward ofthe relief valve main body 81 by the fuel guide portion 84.

Also, (4) in the present embodiment, the fuel guide portion 84 is formedso that a first angle θ1 which is an angle between a first virtualstraight line L1 extending along the outer wall of the first specificshape portion 841 and the axis Ax1 is different from a second angle θ2which is an angle between a second virtual straight line L2 extendingalong the outer wall of the second specific shape portion 842 and theaxis Ax1. In the present embodiment, the second angle θ2 is set to belarger than the first angle θ1. With the above configuration, the fuelflowing from the pressurizing chamber 103 toward the valve seat portion60 can be more effectively guided so as to flow in the directionradially outward of the relief valve main body 81 by the fuel guideportion 84.

(5) In the present embodiment, the fuel guide portion 84 includes thethird specific shape portion 843 that connects the first specific shapeportion 841 to the second specific shape portion 842.

(6) In the present embodiment, the third specific shape portion 843 isformed so that a shape of the outer wall in the cross sectional planewhich is the virtual plane including the axis Ax1 of the fuel guideportion 84 is curved.

With the above configuration, the fuel flowing from the pressurizingchamber 103 toward the valve seat portion 60 can be more effectivelyguided so as to flow in the direction radially outward of the reliefvalve main body 81 by the fuel guide portion 84.

(8) In the present embodiment, the fuel guide portion 84 is formedintegrally with the relief valve main body 81. For that reason, thenumber of members 55 can be reduced.

(10) In the present embodiment, the fuel guide portion 84 is formed suchthat a largest outer diameter is smaller than an inner diameter of theguide hole portion 94. Therefore, the relief valve main body 81 can beinserted into the guide hole portion 94 from the valve seat portion 60of the support portion 90 together with the fuel guide portion 84. Sincethe relatively large chamfered portion 942 is formed on the side of theguide hole portion 94 facing the valve seat portion 60, the relief valvemain body 81 can be easily inserted into the guide hole portion 94 fromthe valve seat portion 60 of the support portion 90 together with thefuel guide portion 84.

(12) In the present embodiment, the valve seat portion 60 has the valveseat cylinder portion 62 that extends in the cylindrical shape from thevalve seat main body 61 toward the first space 105. The support portion90 has the support cylinder portion 92 that extends in the cylindricalshape from the support main body 91 toward the second space 106 and isfitted to the inner wall of the valve seat cylinder portion 62.

As described above, in the present embodiment, since the support portion90 is fitted to the inner wall of the valve seat portion 60, thehardness of the support portion 90 is set to be lower than the hardnessof the valve seat portion 60. For that reason, in the presentembodiment, the guide hole portion 94 (support portion 90) is easilyeroded by the cavitation erosion between the guide hole portion 94 andthe relief valve main body 81. However, in the present embodiment, asdescribed above, since the fuel can be prevented from entering the spacebetween the guide hole portion 94 and the relief valve main body 81 bythe fuel guide portion 84, erosion of the guide hole portion 94 (supportportion 90) can be reduced effectively.

Second Embodiment

A part of a high-pressure pump according to a second embodiment of thepresent disclosure is illustrated in FIG. 8. The second embodiment isdifferent in the shape of a fuel guide portion from the firstembodiment.

In the second embodiment, a fuel guide portion 84 is formed so thatouter walls of a first specific shape portion 841, a third specificshape portion 843, and a second specific shape portion 842 in a crosssection with a virtual plane including an axis Ax1 are shaped along apart of an ellipse An1. The shape of the fourth specific shape portion844 is the same as that of the first embodiment.

In the present embodiment, the ellipse An1 is shaped such that astraight line extending a long axis extends along the outer wall of therelief valve main body 81. The ellipse An1 is shaped such that astraight line extending a short axis extends along the end face of thefirst specific shape portion 841 of the fuel guide portion 84 facing thepressurizing chamber 103.

As described above, (7) in the present embodiment, the fuel guideportion 84 is formed so that the outer walls of the first specific shapeportion 841 and the second specific shape portion 842 in the crosssection with the virtual plane including an axis Ax1 are shaped along apart of the ellipse An1. For that reason, the fuel guide portion 84 cansmoothly guide the fuel in the radially outward direction of the reliefvalve main body 81 when the fuel passes through the fuel guide portion84 from the pressurizing chamber 103 toward the valve seat portion 60.Therefore, the fluid resistance against the relief valve seat 612 in thedirection of the axis Ax1 acting on the relief valve member 80 can bereduced.

Third Embodiment

A part of a high-pressure pump according to a third embodiment of thepresent disclosure is illustrated in FIG. 9. The second embodiment isdifferent in the shape of a fuel guide portion and so on from the firstembodiment.

In the third embodiment, a fuel guide portion 86 is formed separatelywith a relief valve main body 81.

The fuel guide portion 86 is made of a metal such as stainless steel.The fuel guide portion 86 includes a first specific shape portion 861, asecond specific shape portion 862, a base portion 863, and a protrusionportion 864. The first specific shape portion 861, the second specificshape portion 862, the base portion 863, and the protrusion portion 864are integrated together so as to be aligned consecutively in said orderfrom the pressurizing chamber 103 toward the valve seat portion 60. InFIG. 9, a boundary between the first specific shape portion 861 and thesecond specific shape portion 862 is indicated by a two-dot chain line.

The first specific shape portion 861 is formed such that the outer wallof the first specific shape portion 861 increases in its distance fromthe axis Ax2 of the fuel guide portion 86 along a direction from thepressurizing chamber 103 toward the valve seat portion 60. The secondspecific shape portion 862 is formed between the valve seat portion 60and the first specific shape portion 861 so that the outer wall of thesecond specific shape portion 862 increases in its distance from theaxis Ax2 along the direction from the pressurizing chamber 103 towardthe valve seat portion 60. The first specific shape portion 861 and thesecond specific shape portion 862 are formed so that a shape of theouter wall of each shape portion is linear in a cross sectional planewhich is the virtual plane including the axis Ax2. In other words, thefirst specific shape portion 861 and the second specific shape portion862 are tapered so that a diameter reduction ratio, which is a ratio atwhich the outer diameter decreases according to a positional change inthe direction of the axis Ax2, is kept constant.

The fuel guide portion 86 is formed so that a first angle θ3 which is anangle between a first virtual straight line L3 extending along the outerwall of the first specific shape portion 861 and the axis Ax2 is thesame as a second angle θ4 which is an angle between a second virtualstraight line L4 extending along the outer wall of the second specificshape portion 862 and the axis Ax2. In the present embodiment, the firstangle θ3 and the second angle θ4 are set to, for example, approximately45 degrees.

The base portion 863 is formed on a side of the second specific shapeportion 862 facing the valve seat portion 60. The base portion 863 isformed in a substantially columnar shape. An outer diameter of the baseportion 863 is the same as the outer diameter of the end portion of thesecond specific shape portion 862 facing the valve seat portion 60 andis kept constant in the direction of the axis Ax2.

The protrusion portion 864 is formed so as to project in a substantiallycolumnar shape from a center of the base portion 863 toward the valveseat portion 60. The outer diameter of the protrusion portion 864 issmaller than the outer diameter of the base portion 863. Therefore, alargest outer diameter of the fuel guide portion 86 is the outerdiameter of the base portion 863. The relief valve main body 81 has arecess portion 813 that is recessed toward the valve seat portion 60from the end face facing the pressurizing chamber 103.

The fuel guide portion 86 is provided at the end portion of the reliefvalve main body 81 facing the pressurizing chamber 103 by fitting theprotrusion portion 864 into the recess portion 813. In this example, theouter diameter of the base portion 863 of the fuel guide portion 86,that is, the largest outer diameter of the fuel guide portion 86 isformed to be larger than the outer diameter of the end portion of therelief valve main body 81 facing the pressurizing chamber 103 and theinner diameter of the guide hole portion 94.

As described above, (3) in the present embodiment, the fuel guideportion 86 includes the first specific shape portion 861 in which theouter wall increases in its distance from the axis Ax2 of the fuel guideportion 86 along the direction toward the valve seat portion 60 from thepressurizing chamber 103, and the second specific shape portion 862which is formed between the valve seat portion 60 and the first specificshape portion 861 so that the outer wall of the second specific shapeportion 862 increases in its distance from the axis Ax2 in the directiontoward the valve seat portion 60 from the pressurizing chamber 103. Withthe above configuration, the fuel flowing from the pressurizing chamber103 toward the valve seat portion 60 can be effectively guided so as toflow in the direction radially outward of the relief valve main body 81by the fuel guide portion 86.

In the present embodiment, the fuel guide portion 86 is formed so that afirst angle θ3 which is an angle between a first virtual straight lineL3 extending along the outer wall of the first specific shape portion861 and the axis Ax2 is the same as a second angle θ4 which is an anglebetween a second virtual straight line L4 extending along the outer wallof the second specific shape portion 862 and the axis Ax2.

(9) In the present embodiment, the fuel guide portion 86 is formedseparately from the relief valve main body 81. For that reason, the fuelguide portion 86 can be machined separately from the relief valve mainbody 81. Therefore, the influence of the processing of the fuel guideportion 86 on the relief valve main body 81 can be reduced.

(11) In the present embodiment, the fuel guide portion 86 is formed suchthat a largest outer diameter of the fuel guide portion 86 is largerthan an inner diameter of the guide hole portion 94. For that reason,the fuel guide portion 86 blocks the fuel flowing from the pressurizingchamber 103 to the valve seat portion 60, thereby being capable of moreeffectively preventing the fuel from entering a space between the guidehole portion 94 and the relief valve main body 81. As a result, therelief valve seat 612 or the relief valve seat portion 85 can beeffectively prevented from being worn, and a change over time in thevalve opening pressure of the relief valve member 80 can be moreeffectively reduced.

Other Embodiments

In the embodiments described above, the support main body 91 of thesupport portion 90 slidably supports the outer wall of the other endside of the relief valve main body 81, that is, the end portion facingthe pressurizing chamber 103. In contrast, in another embodiment of thepresent disclosure, the support main body 91 of the support portion 90may slidably support any position of the relief valve main body 81 inthe axial direction. In other words, a distance between the fuel guideportion and the guide hole portion 94 may be set arbitrarily.

Further, in the first embodiment, the fuel guide portion 84 includes thefirst specific shape portion 841, the second specific shape portion 842,the third specific shape portion 843, and the fourth specific shapeportion 844, and the third specific shape portion 843 is formed so thatthe shape of the outer wall is curved in the cross sectional plane whichis the virtual plane including the axis Ax1 of the fuel guide portion86. In contrast, according to another embodiment of the presentdisclosure, the third specific shape portion 843 may be formed such thatthe shape of the outer wall is linear in the cross sectional plane whichis the virtual plane including the axis Ax1.

Further, the fuel guide portion 84 may not have the third specific shapeportion 843, and the first specific shape portion 841 and the secondspecific shape portion 862 may be connected to each other. In addition,the first angle θ1 and the second angle θ2 may be set to any size aslong as those angles are larger than 0 degrees and smaller than 90degrees. In addition, the first angle θ1 and the second angle θ2 may bethe same in degree. Even if the first angle θ1 and the second angle θ2are the same in degree as each other, the fuel guide portion 84 canobtain the effect of guiding the fuel so that the fuel passing throughthe fuel guide portion 84 from the pressurizing chamber 103 toward thevalve seat portion 60 flows in the radially outward direction of therelief valve main body 81.

The outer diameter of the end portion of the fourth specific shapeportion 844 facing the relief valve main body 81, that is, the largestouter diameter of the fuel guide portion 84 may be formed to be equal toor larger than the inner diameter of the guide hole portion 94. Further,the fuel guide portion 84 may be configured not to have the fourthspecific shape portion 844. The fuel guide portion 84 may be formedseparately from the relief valve main body 81.

In the second embodiment, the fuel guide portion 84 is formed so thatthe outer walls of the first specific shape portion 841 and the secondspecific shape portion 842 in the cross sectional plane which is thevirtual plane including the axis Ax1 are shaped along a part of theellipse An1. In contrast, in another embodiment of the presentdisclosure, the fuel guide portion 84 may be formed so that the outerwalls of the first specific shape portion 841 and the second specificshape portion 842 in the cross sectional plane which is the virtualplane including an axis Ax1 are shaped along a part of a circle.

In the third embodiment, the fuel guide portion 86 is formed such thatthe first angle θ3 and the second angle θ4 are formed to be the same aseach other. In contrast, in another embodiment of the presentdisclosure, the fuel guide portion 86 may be formed so that the firstangle θ3 and the second angle θ4 are different from each other. As inthe first embodiment, a third specific shape portion may be providedbetween the first specific shape portion 861 and the second specificshape portion 862. The outer diameter of the base portion 863, that is,the maximum outer diameter of the fuel guide portion 86 may be equal toor smaller than the inner diameter of the guide hole portion 94, forexample, the same as the outer diameter of the end portion of the reliefvalve main body 81 facing the pressurizing chamber 103. The fuel guideportion 86 may be formed integrally with the relief valve main body 81.

Further, in the embodiments described above, the example in which thesupport cylinder portion 92 of the support portion 90 is fitted to theinner wall of the valve seat cylinder portion 62 of the valve seatportion 60 is shown. On the contrary, in another embodiment of thepresent disclosure, the support cylinder portion 92 may be fitted to theouter wall of the valve seat cylinder portion 62.

Further, in another embodiment of the present disclosure, the valve seatportion 60 may not have the valve seat cylinder portion 62. Further, thesupport portion 90 may not have the support cylinder portion 92. Inother words, the valve seat portion 60 and the support portion 90 maynot be fitted to each other. In this case, it is conceivable to providethe support portion 90 (the support main body 91) by being fitted to theinner wall of the upper housing 11 forming the discharge hole portion112. In addition, the hardness of the support portion 90 may be set tobe equal to or higher than the hardness of the valve seat portion 60 andthe relief valve member 80.

Further, in the embodiments described above, the side of the guide holeportion 94 facing the pressurizing chamber 103 has the chamfered portion941 having the size C0.1 or less. From the viewpoint of reducing theentry of the fuel between the guide hole portion 94 and the relief valvemain body 81, it is preferable that the size of the chamfered portion941 is as small as possible, but in another embodiment of the presentdisclosure, the chamfered portion 941 may be set to be larger than C0.1.Further, the guide hole portion 94 may have a configuration without thechamfered portion 941 (i.e. C0). Further, in another embodiment of thepresent disclosure, at least two of the cylinder, the upper housing, andthe lower housing may be integrated together.

Further, in another embodiment of the present disclosure, the intakevalve device may configure a normally closed type (normally closed valvetype) valve device together with an electromagnetic drive portion.Further, as long as the intake valve device configures a normally closedtype valve device, there is no need to provide the electromagnetic driveportion.

In another embodiment of the present disclosure, the pulsation dampermay not be installed inside the cover. Further, the cover may not beprovided. In the case of the configuration without the cover member, itis conceivable to directly supply the fuel to the intake passage of thepump body.

In another embodiment of the present disclosure, the high-pressure pumpmay be used as a fuel pump that discharges the fuel toward a device orthe like other than the engine of the vehicle. As described above, thepresent disclosure is not limited to the above embodiments, but can beimplemented in various configurations without departing from the spiritof the present invention.

While the present disclosure has been described with reference toembodiments thereof, it is to be understood that the disclosure is notlimited to the embodiments and constructions. To the contrary, thepresent disclosure is intended to cover various modification andequivalent arrangements. In addition, while the various elements areshown in various combinations and configurations, which are exemplary,other combinations and configurations, including more, less or only asingle element, are also within the spirit and scope of the presentdisclosure.

The invention claimed is:
 1. A high-pressure pump comprising: a pumpbody including a pressurizing chamber that pressurizes a fuel, and adischarge passage through which the fuel pressurized and discharged bythe pressurizing chamber flows; a valve seat portion that includes avalve seat main body which is provided in the discharge passage topartition the discharge passage into a first space positioned betweenthe valve seat main body and the pressurizing chamber and a second spacepositioned on an opposite side of the valve seat main body from thepressurizing chamber, a discharge valve passage which is provided in thevalve seat main body and connects the first space and the second space,a relief valve passage which is provided in the valve seat main body andconnects the second space and the first space without communicating withthe discharge valve passage, a discharge valve seat having an annularshape and surrounding an opening of the discharge valve passage of thevalve seat main body in the second space, and a relief valve seat havingan annular shape and surrounding an opening of the relief valve passageof the valve seat main body in the first space; a discharge valve memberprovided in the second space to be capable of contacting the dischargevalve seat, the discharge valve member opening or closing the dischargevalve passage when separating from the discharge valve seat orcontacting the discharge valve seat; a discharge valve urging memberurging the discharge valve member toward the discharge valve seat; arelief valve member provided in the first space to be reciprocable in anaxial direction, the relief valve member including a relief valve mainbody having a rod shape, and a relief valve seat portion which isintegrated with a first end of the relief valve main body in the axialdirection and is capable of contacting the relief valve seat; a reliefvalve urging member urging the relief valve member toward the reliefvalve seat; a support portion including a support main body provided inthe first space, and a guide hole portion connecting a surface of thesupport main body facing the pressurizing chamber and a surface of thesupport main body facing the valve seat portion, the relief valve mainbody being inserted into the guide hole portion, the support portionslidably supporting an outer wall of the relief valve main body by theguide hole portion to guide reciprocating movement of the relief valvemember in the axial direction; and a fuel guide portion that is providedon an end portion of the relief valve main body facing the pressurizingchamber and is capable of guiding a flow of the fuel in a directionradially outward of the relief valve main body on the way from thepressurizing chamber to the valve seat portion wherein the fuel guideportion includes a first specific shape portion having an outer wallwhich increases in its distance from an axis of the fuel guide portionalong a direction from the pressurizing chamber toward the valve seatportion, and a second specific shape portion disposed between the valveseat portion and the first specific shape portion, the second specificshape portion having an outer wall which increases in its distance fromthe axis along the direction from the pressurizing chamber toward thevalve seat portion, and a first angle between a first virtual straightline extending along the outer wall of the first specific shape portionand the axis is different from a second angle between a second virtualstraight line extending along the outer wall of the second specificshape portion and the axis.
 2. The high-pressure pump according to claim1, wherein the guide hole portion of the support portion slidablysupports the outer wall of the relief valve main body at a second end ofthe relief valve main body in the axial direction.
 3. The high-pressurepump according claim 1, wherein the fuel guide portion has a thirdspecific shape portion that connects the first specific shape portionand the second specific shape portion.
 4. The high-pressure pumpaccording to claim 3, wherein an outer wall of the third specific shapeportion is curved in a cross sectional plane which is a virtual planeincluding the axis of the fuel guide portion.
 5. The high-pressure pumpaccording to claim 1, wherein the fuel guide portion is integrated withthe relief valve main body.
 6. The high-pressure pump according to claim1, wherein the fuel guide portion is separate from the relief valve mainbody.
 7. The high-pressure pump according to claim 1, wherein a largestouter diameter of the fuel guide portion is smaller than an innerdiameter of the guide hole portion.
 8. The high-pressure pump accordingto claim 1, wherein a largest outer diameter of the fuel guide portionis equal to or larger than an inner diameter of the guide hole portion.9. The high-pressure pump according to claim 1, wherein the valve seatportion includes a valve seat cylinder portion extending in acylindrical shape from the valve seat main body toward the first space,and the support portion includes a support cylinder portion extending ina cylindrical shape from the support main body toward the second spaceand being fitted to an inner wall or an outer wall of the valve seatcylinder portion.
 10. A high-pressure pump comprising: a pump bodyincluding a pressurizing chamber that pressurizes a fuel, and adischarge passage through which the fuel pressurized and discharged bythe pressurizing chamber flows; a valve seat portion that includes avalve seat main body which is provided in the discharge passage topartition the discharge passage into a first space positioned betweenthe valve seat main body and the pressurizing chamber and a second spacepositioned on an opposite side of the valve seat main body from thepressurizing chamber, a discharge valve passage which is provided in thevalve seat main body and connects the first space and the second space,a relief valve passage which is provided in the valve seat main body andconnects the second space and the first space without communicating withthe discharge valve passage, a discharge valve seat having an annularshape and surrounding an opening of the discharge valve passage of thevalve seat main body in the second space, and a relief valve seat havingan annular shape and surrounding an opening of the relieve valve passageof the valve seat main body in the first space; a discharge valve memberprovided in the second space to be capable of contacting the dischargevalve seat, the discharge valve member opening or closing the dischargevalve passage when separating from the discharge valve seat orcontacting the discharge valve seat; a discharge valve urging memberurging the discharge valve member toward the discharge valve seat; arelief valve member provided in the first space to be reciprocable in anaxial direction, the relief valve member including a relief valve mainbody having a rod shape, and a relief valve seat portion which isintegrated with a first end of the relief valve main body in the axialdirection and is capable of contacting the relief valve seat; a reliefvalve urging member urging the relief valve member toward the reliefvalve seat; a support portion including a support main body provided inthe first space, and a guide hole portion connecting a surface of thesupport main body facing the pressurizing chamber and a surface of thesupport main body facing the valve seat portion, the relief valve mainbody being inserted into the guide hole portion, the support portionslidably supporting an outer wall of the relief valve main body by theguide hole portion to guide reciprocating movement of the relief valvemember in the axial direction; and a fuel guide portion that is providedon an end portion of the relief valve main body facing the pressurizingchamber and is capable of guiding a flow of the fuel in a directionradially outward of the relief valve main body on the way from thepressurizing chamber to the valve seat portion, wherein the fuel guideportion includes a first specific shape portion having an outer wallwhich increases in its distance from an axis of the fuel guide portionalong a direction from the pressurizing chamber toward the valve seatportion, and a second specific shape portion disposed between the valveseat portion and the first specific shape portion, the second specificshape portion having an outer wall which increases in its distance fromthe axis along the direction from the pressurizing chamber toward thevalve seat portion, and the outer walls of the first specific shapeportion and the second specific shape portion of the fuel guide portionhave shapes along a part of a circle or a part of an ellipse in a crosssectional plane which is a virtual plane including the axis.
 11. Thehigh-pressure pump according to claim 10, wherein a first angle betweena first virtual straight line extending along the outer wall of thefirst specific shape portion and the axis is different from a secondangle between a second virtual straight line extending along the outerwall of the second specific shape portion and the axis.
 12. Ahigh-pressure pump comprising: a pump body including a pressurizingchamber that pressurizes a fuel, and a discharge passage through whichthe fuel pressurized and discharged by the pressurizing chamber flows; avalve seat portion that includes a valve seat main body which isprovided in the discharge passage to partition the discharge passageinto a first space positioned between the valve seat main body and thepressurizing chamber and a second space positioned on an opposite sideof the valve seat main body from the pressurizing chamber, a dischargevalve passage which is provided in the valve seat main body and connectsthe first space and the second space, a relief valve passage which isprovided in the valve seat main body and connects the second space andthe first space without communicating with the discharge valve passage,a discharge valve seat having an annular shape and surrounding anopening of the discharge valve passage of the valve seat main body inthe second space, and a relief valve seat having an annular shape andsurrounding an opening of the relieve valve passage of the valve seatmain body in the first space; a discharge valve member provided in thesecond space to be capable of contacting the discharge valve seat, thedischarge valve member opening or closing the discharge valve passagewhen separating from the discharge valve seat or contacting thedischarge valve seat; a discharge valve urging member urging thedischarge valve member toward the discharge valve seat; a relief valvemember provided in the first space to be reciprocable in an axialdirection, the relief valve member including a relief valve main bodyhaving a rod shape, and a relief valve seat portion which is integratedwith a first end of the relief valve main body in the axial directionand is capable of contacting the relief valve seat; a relief valveurging member urging the relief valve member toward the relief valveseat; a support portion including a support main body provided in thefirst space, and a guide hole portion connecting a surface of thesupport main body facing the pressurizing chamber and a surface of thesupport main body facing the valve seat portion, the relief valve mainbody being inserted into the guide hole portion, the support portionslidably supporting an outer wall of the relief valve main body by theguide hole portion to guide reciprocating movement of the relief valvemember in the axial direction; and a fuel guide portion that is providedon an end portion of the relief valve main body facing the pressurizingchamber and is capable of guiding a flow of the fuel in a directionradially outward of the relief valve main body on the way from thepressurizing chamber to the valve seat portion, wherein the fuel guideportion is separate from the relief valve main body, and a largest outerdiameter of the fuel guide portion is equal to or larger than an innerdiameter of the guide hole portion.
 13. The high-pressure pump accordingto claim 12, wherein the fuel guide portion includes a first specificshape portion having an outer wall which increases in its distance froman axis of the fuel guide portion along a direction from thepressurizing chamber toward the valve seat portion, and a secondspecific shape portion disposed between the valve seat portion and thefirst specific shape portion, the second specific shape portion havingan outer wall which increases in its distance from the axis along thedirection from the pressurizing chamber toward the valve seat portion.